Mechanical stoker



March 22, 1932. C A WAECHTER 1,850,428

MECHANICAL STOKER Filed July 20, 1929 2 Sheets-Sheet l l ZM March 22, 1932. Q A WAECHTER I 1,850,428

MECHANICAL STOKER Filed July 20, 1929 2 Sheets-Sheet 2 pwyENToR I Q- aw Patented Mar. 22, 1932 CHARLES A. WAECH'I'ER, OF ROSS TOWNSHIP, ALLEGHENY COUNTY, PENNSYLVANIA,

ASSIGNOR TO PITTSBURGH STOKER COMPANY, INC., OF ROSS TOWNSHIP,

PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA MECHANICAL STOKER Application filed July 20,

The object which I have in view is the improvement in the general type of mechanical stoker shown and described in United States LettersPatent No. 1,813,262, issued July 7 1931 to Truman R. Snyder, assignor to Frederick C. Hinkel.

Among such improvements are the following The simplification of the construction of the stoker whereby its structure is rendered more durable and efficient in operation.

The improvement of the driving connections of the worm conveyer.

The provision of improved means for ad j usting the intermittent feeding movement of the worm conveyer.

The improvement of the drive of the rotary ejector which discharges the fuel, supphed by the conveyer, into the fire box of the furnace.

The improvement in the structure and arrangement of the ejector chamber,

Other improvements in construction, and also in arrangement of parts, W111 appear from the following description.

In the accompanying drawings, wherein 1 have illustrated a practical embodiment of the principles of my invention, Fig. 1 1s a side elevation of the stoker, the conveyer trough and the gear case, being partially broken away in vertical section to show the parts and the motor being omitted;

Fig. 2 is adiagrammatic view, partially in plan and partially in horizontal section, illustrating the driving connections;

Fig. 3 is an end view looking from the left in Fig. 1;

Fig. 4 is an opposite end view;

Fig. 5 is a detail of the drive of the conveyer worm, partly in section;

Fig. 6 is a sectional view taken along the line 66 in Fig. 1.

Referring-to the drawings, 1 represents a platform which is supported at the proper elevation as by the legs 2. Upon the platform is carried the gear case 3 from which posts 4 extends upwardly to support the horizontally disposed conveyer'trough 5 which is preferably ofrthe characteristic cross sec- 1929. Serial No. 379,600.

tional shape illustrated in the drawings, the side walls of the trough diverging upwardly.

The front end of the trough 5, the right end in Fig. 1, is. provided with an end plate 6 and outside of the end plate with a flexiblejoint case 7, the plate and case being detachably held in position, as by the bolts 8 which are screwed into threaded socket-holes in the walls of the trough 5.

A shaft 9 is disposed longitudinally of and in the trough 5 and has mounted thereon the conveyer worm 10.

The case 7 contains a flexible shaft joint which may comprise the metal disks 11 and 12 and the intermediate flexible disk, such as the fibre disk 13, said disks being spaced apart and connected in the usual manner as by pins 14.

The front end of the shaft 9 extends through a hole in the plate 6 and is socketed to receive the stud 15 which extends from the adjacent disk 11 so that the shaft will rotate with the disk.

The opposite or rear end of the shaft 9 is preferably unprovided with a bearing, so that the conveyer worm floats.

Integral with the casing 7 is an outwardly extending tubular hub 16 whose perimetral surface is composed of a portion 17 adjacent tothe casingof greater diameter and an outer portion 18 of lesser diameter with an an nular shoulder 19 between them.

Within the hub 16 is the bushing 20 in which is j ournaled the stub shaft'21 fixed to the disk 12 and axially alined with the stud 15. Pinned or otherwise secured to the protruding outer end of the shaft 21 is the ratchet gear 22.

23 represents a tubular dog-carrier which has a tubular neck which is journaled on the hub-portion 18 of the case 7 and an enlarged interior bore which surrounds the gear 22. The gear when mounted on the shaft 21 prevents the clisassemblage of the carrier from the case while permitting the rotation of the carrier relative to the case.

The outer end of the carrier is closed by a detachable cover 24- through which may extend the grease cup 25 by means of which the "ratchet wheel and the shaft may be kept V lubricated. V I

The carrier 23 is provided with one or more radially disposed seats 26 in which are slid ably mounted the dogs 27, the outer ends of the seats being closed by removable covers 28 for the convenient insertion or removal of the dogs. The dogs are spring pressed against the perimeter of the gear 22 by means 0 springs 29 compressed between the outer ends of the dogs and the covers. It is evident that should the carrier 23 be rotated clockwise in Fig. 5, the gear 22 and the shaft 9 will be rotated in like manner, while a counterclockwise rotation of the carrier would result in the dogs trailing idly over the gear without rotating the latter.

1. A lever 30 is fixed to the carrier 23 and extends radially thereof, and the outer end of the'lever is provided with an eye-member 31 which'is pivoted as by a bolt to the forked end of a rod 32 which is provided adjacent to "its other end with a longitudinally dis posed slotted opening 33 whose outer end wall is provided with a threaded hole 34.

' 35 represents a bell-crank pivoted at its angle 36 on the table 1. One end of the bellcrank isprovided with a Vertically disposed and interiorly threaded sleeve 37 and 38 is a bolt whose lower end isscrewed through said sleeve.

The slotted portion of the rod 32 is provided with a detachable cover 39 having a slot of narrower width which is 'suflicient to receive the shank of the bolt 38 with the head of the bolt bearing on the cover. The bolt is provided with a bushing 40 which slidably fits the slot 33 in the rod 32. A. look nut 41 may be screwed up on the lower end of the bolt.

The inner end of the slot in-the rod 32 is semi-circular to fit the bushing 40. A block 42 is slidably mounted in the slot 33 in the rod 32 and has a semi-circular face to fit the bushing 40. Said block is attached to the inner end of a screw shaft 43 so that the shaft may rotate relative to the block, and said shaft is screwed through the threaded hole 34 and has its outer end provided with a hand crank 44: so that the shaft may be turned to move the block along the slot in the rod. I The other end of. the bell-crank 35 is pivotally connected to the arm 45 of aneccentr-ic strap 46 which encircles an eccentric disk? mounted on a vertical shaft 48 journaledinthe cover and bottom of the gear case3. A worm gear 49, 'is' mounted on said shaft within said case and is in mesh with a worm 50 on a shaft 51 which is coupled to the motor 52 mounted on the table 1, as by the flight'50a. g j p I It is evident that the rotation by the motor of the worm gear and the eccentric will cause the bell-crank to oscillate and thus oscillate the dog-carrier 23,thus imparting an intermittent rotation of the worm conveyor 10.

The are of movements of the dog-carrier 23.

may be regulated by adjusting the block 42 along the slot 33 in the rod 32. When the block is moved inwardly along the'slot so that the bushing 40 is held between the block and the inner end of the slot and is thus prevented from movement longitudinally of the slot, the dog-carrier receives the full throw of the rod 32 impartedito the latter bythe oscillations of the bell-crank. "However; by adjusting the block along the slot a lost motion of greater or less extent, as may be desired, is provided during which the bolt 38,

will move along the slot before'engaging the block or the end of the slot. Thus the throw of'the dog-carrier and consequently the arc of the intermittent rotary movements of the worm conveyor may be regulated to provide the volume of feed desired. r I i The front portion of the trough is open at its top and a fuel-hopper 53'is mounted thereon, the throat of the hopper being in open communication with the trough while the upper end or mouth of theihopper may be provided with a screen which is indicated at 54 in dotted lines in Fig. 4 to prevent fuel lumps of excess size being supplied. to the conveyer worm. The rear portion ofthe trough is provided with a'lid 55 which may be bolted in place. At the rear or discharge end of the trough 5, the left endin Fig. 1, is the ejector case 56 which is preferably a separate element bolted or otherwise secured to the end of the trough. The upper portion of the case 56 forms a chamber 57 which is located at the end of the trough 5 and into which the end of the conveyor extends, so that such chamber receives the fuel which is delivered by the conveyor worm. The lower. portion of the case 56 is offset forwardly and provides the ejector chamber 58 which is in communication at its top with the chamber 57 The front of the ejector chamber is provided with the opening 59 so that when the stoker is in position the opening may register with the fuel doorway of the furnace whose walls are indicated at 60 in dotted lines in Fig. 2.

The shaft 51 extends through the front and rear walls of the case 56, extending across the chamber 58 and the rear end of theshaft is journaled in a ball bearing 61 carriedby a bearing-housing 62 mounted on and extending rearwardly of thecase 56. Thus the bearings of the shaft 51'are'out of the path of fuel dust. I

Mounted on the shaft 51' and working within the ejector chamber 58 is the rotary ejector 63which is in the form of a double paddle blade mounted at its center-on the shaft. w

'The fuel is discharged'b "the conveyor worm onto the ejector and y it is thrown out through the opening or port 59 into the furnace in the form of a more or less dense cloud which settles evenly on the fuel bed maintaining an even and highly efficient combustion of fuel. It is evident that the ejector is driven at much higher speed than is the worm conveyor.

.My improved stoker is a compact mechanism which occupies but little space in the furnace or boiler room, and it may be sold at a relatively low price. It is simple and durable and does not require skill or much attention for its operation.

What I desire to claim is 1. The combination with a mechanical stoker comprising a conveyer trough at one end of which the fuel is admitted and at the other end of which the fuel is ejected into the furnace, a conveyer worm working in said trough and a ratchet mechanism operatively connected to the intake end of the conveyer worm, of an operating rod connected to said ratchet mechanism, said rod being provided with an elongated opening in its 5 outer end, means for adjusting the effective length of. said opening, a block slidably mounted in said opening and arranged for movement longitudinally thereof, and means for oscillating said block whereby the ratchet mechanism may be operated, the throw of said ratchet mechanism being regulated by adj usting the effective length of said opening.

2. The combination with a mechanical stoker comprising a conveyer trough at one 5 end of which the fuel is admitted and at the other end of which the fuel is ejected into the furnace, a conveyer worm working in said trough and a ratchet mechanism operatively connected to the intake end of the conveyer worm, of an operating rod connected to said ratchet mechanism, said rod being provided with an elongated opening in its outer end, a block slidably mounted in said opening so as to be adjusted toward or away from the inner end of said opening, the outer end of said rod being provided with a threaded hole extending into said opening, a screw engaging said threaded hole and having its inner end connected to said block so as to rotate relative thereto, a second block slidably mounted in said opening between the inner end of the latter and said first mentioned block, and means whereby to oscillate the second mentioned block whereby to operate said ratchet mechanism, the throw of the ratchet mechanism being regulated by adjustment of the position of said first mentioned block relative to said opening.

In testimony whereof, I hereunto aflix my signature.

CHAS. A. WAECHTER. 

